Organic electroluminescent display device

ABSTRACT

An organic electroluminescent display device includes a display region configured to display pixels; a frame region configured to surround the display region; a substrate; an organic electroluminescent element disposed on the substrate; a sealing member configured to cover the organic electroluminescent element; a lead wire disposed on the substrate and extending from a region covered with the sealing member to an outer side of the sealing member; and one or more organic insulators disposed within the frame region instead of within the display region. The lead wire includes two opposite side portions. The one organic insulator or each organic insulator covers part of at least one of the two side portions. The sealing member covers the one or more organic insulators.

TECHNICAL FIELD

The present disclosure relates to organic electroluminescent displaydevices (hereinafter also referred to as “organic EL display devices”).More specifically, the present disclosure relates to an organic ELdisplay device suitable as a display device including an organicelectroluminescent element in each pixel (hereinafter the element isalso referred to as an “organic EL element”).

BACKGROUND ART

In recent years, flat panel displays have been used in various productsor various fields. Such flat panel displays have been required to have alarger size and a higher quality and to reduce power consumption.

In these circumstances, organic EL display devices including organic ELelements that utilize electroluminescence of organic materials have beenattracting great attention as all-solid flat panel displays excellent interms of, for example, being driven at low voltages and having fastresponse time and self-luminousness.

An organic EL element includes a pair of electrodes functioning as ananode and a cathode and an electroluminescence layer (hereinafter alsoreferred to as an “EL layer”) disposed between the paired electrodes. Anorganic EL element is typically subject to moisture and oxygen.Intrusion of moisture and/or oxygen into an organic EL element promotesdegradation of element properties of the organic EL element such asluminance. Various opinions have been offered about this degradationmechanism. One of them expresses that the degradation occurs due tooxidization or hydroxidization of a luminescent material and/or acathode material. To inhibit degradation of organic EL elements, organicEL display devices are usually subjected to sealing. Specifically, forexample, a sealant is provided around an organic EL element and a spaceenclosed with the sealant is filled with a resin desiccating agent.

Other examples of the technology for improving resistance of an organicEL element to moisture and oxygen include the followings.

Disclosed is a light emitting device in which a multilayer structureincluding an inorganic film, an organic film, and an inorganic film isnot continuously provided from a lower portion of a sealant to a lowerportion of a cathode of a light-emitting element (see, for example, PTL1).

Also disclosed is an organic EL element that at least includes a firstsubstrate, a sealing substrate opposing the first substrate while havinga distance from the first substrate, a sealant that seals the firstsubstrate and the sealing substrate and forms a sealed space between thefirst substrate and the sealing substrate, a source line and a gate linedisposed on the first substrate, and a pixel electrode electricallyconnected to the gate line and the source line. The source line and thegate line are disposed in the sealed space. The organic EL elementincludes a source lead electrode that is connected with the source lineand drawn from the sealed space. The source lead electrode is formed ofthe same film as the gate line (see, for example, PTL 2).

Also disclosed is a display device in which a layer containing awater-permeable organic material is sealed with a sealant (see, forexample, PTL 3).

Also disclosed is a light emitting device that includes a substrate, alight-emitting element including an organic electroluminescence layerbetween a pair of electrodes stacked on the substrate in a thicknessdirection of the substrate, a lead wire disposed on the substrate andconnected with the pair of electrodes of the light-emitting element, anda sealing member that seals the light-emitting element. An insulatinglayer containing an inorganic oxide is disposed on the substrate at atleast a portion around the light-emitting element. The sealing member isbonded to the insulating layer containing the inorganic oxide anddisposed around the light-emitting element using an adhesive interposedbetween the sealing member and the insulating layer (see, for example,PTL 4).

Also disclosed is an organic EL display device including a devicesubstrate on which a pixel region is formed by arranging multiple pixelsin a matrix, an organic EL element and a driving transistor for drivingthe organic EL element disposed in each pixel of the pixel region, andtwo inter-organic-layer insulating films disposed above the drivingtransistors and below the organic EL elements. A sealing substrate isbonded to the device substrate using a sealing member disposed over aregion surrounding a pixel region. The two inter-organic-layerinsulating films are divided by a dividing region disposed between thesealing member and the pixel region (see, for example, PTL 5).

Also disclosed is an organic electronics panel including an organicelectronics element. In the organic electronics element, an organiccompound layer, including a functional layer containing at least anorganic compound, is tightly held between a pair of electrodes disposedon a support substrate. The organic electronics element is tightlysealed with a sealing member, covering the organic electronics element,between the sealing member and the support substrate in the state wherethe electrodes and the organic compound layer are tightly held. Ajunction of a lead portion of one of the electrodes and an electrodelead for connection with an external driving circuit is located within atightly sealed region covered with the sealing member. The electrodelead is drawn from the tightly sealed region (see, for example, PTL 6).

Also disclosed is a display device including a support substrate, onwhich a display region is formed by arranging organic EL elements and asurrounding region is formed by disposing an organic-EL-element drivingcircuit around the display region. The organic EL element is sealed byan opposing substrate using a sealing resin. A wire is disposed in thesurrounding region on the support substrate in which the driving circuitis disposed. An insulating film and a separation groove, which dividesthe insulating film, are also disposed on the support substrate. Aprotrusion is disposed on the opposing substrate at a portion opposingthe separating groove. The protrusion is inserted into the separationgroove (see, for example, PTL 7).

Also disclosed is a display device in which a sealant is disposed aroundan inter-layer insulator to prevent moisture or oxygen from intrudingthrough an exposed portion of the inter-layer insulator (see, forexample, PTL 8).

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No.2011-228315

PTL 2: Japanese Unexamined Patent Application Publication No.2006-164737

PTL 3: Japanese Unexamined Patent Application Publication No. 2006-65320

PTL 4: Japanese Unexamined Patent Application Publication No.2008-192426

PTL 5: Japanese Unexamined Patent Application Publication No.2004-335267

PTL 6: International Publication No. 2010/150648

PTL 7: Japanese Unexamined Patent Application Publication No.2012-134173

PTL 8: Japanese Unexamined Patent Application Publication No.2005-100979

SUMMARY Technical Problem

Employing these measures, however, has not yet attained sufficientinhibition of degradation and further inhibition of degradation isrequired.

An organic EL display device that the inventors have examined includes asubstrate, an organic EL element disposed on the substrate, and asealing member configured to cover the organic EL element. In addition,a lead wire is disposed on the substrate. The lead wire is drawn to theoutside of the sealing member from a sealed region sealed by thesubstrate and the sealing member. If a wire formed by stacking two ormore layers such as titanium (Ti)-aluminum (Al)-titanium (Ti) layers (ora multilayer wire) is used as this lead wire, the moisture and oxygen inthe air are highly likely to intrude from the outside into the sealedregion along the side portions of the lead wire. The reason for this isdescribed as follows.

The etching rate varies between two or more layers included in themultilayer wire and the amount of side etching thus varies between thoselayers. The side portions of the multilayer wire are thus likely to havean overhanging shape, that is, a shape in which the topmost layer sticksout sideways. It is usually difficult to sufficiently cover the sideportions having such a shape with a sealant or an inorganic barrier filmformed by plasma chemical vapor deposition (CVD). This is because suchan inorganic barrier film typically has a poor property of coveringstepped portions and the sealant typically has high viscosity. Thus, theinventor has noted that using a multilayer wire as a lead wire highlylikely causes gaps between the side portions of the lead wire and theinorganic barrier film or the sealant along the side portions of thelead wire and these gaps are used as intrusion paths for moisture andoxygen into the sealed region.

In the display device described in PTL 8, for example, a sealant isdisposed immediately above the lead wire for inputting signals to thedisplay region. Thus, if, for example, a Ti—Al—Ti multilayer wire isused as a lead wire, the coverage of the sealant would be insufficientdue to the above-described problem of the shape of the side portions andintrusion paths for the moisture and oxygen would be finally formedalong the side portions of the lead wire. Degradation of thelight-emitting element would thus be promoted.

To solve such problems, it is conceivable to form on a lead wire anorganic insulating film made of an organic material, for example, aninter-layer insulating film. In this case, however, it is concerned thatmoisture and oxygen may intrude into the sealed region through aclearance between the sealant and the organic insulating film. This isbecause the adhesion of the sealant to the organic insulating film isgenerally poor and the sealant and the organic insulating film are morelikely to be separated at the interface therebetween.

FIGS. 43(a) to 43(c) are schematic diagrams of the light emitting devicedescribed in PTL 1, where FIG. 43(a) is a cross-sectional view of thelight emitting device taken along the line A-B in FIG. 43(b), FIG. 43(b)is a plan view of the light emitting device, and FIG. 43(c) is across-sectional view of the light emitting device taken along the lineC-D in FIG. 43(b). FIGS. 44(a) and 44(b) are schematic cross-sectionalviews of the light emitting device described in PTL 1 in the case wherea particle adheres to a wire.

As illustrated in FIGS. 43(a) to 43(c), the display device described inPTL 1 includes a substrate 1000, a primary insulator film 1001 disposedon the substrate 1000, an organic insulating film 1002, a wire 1003 anda lower electrode 1004 disposed on the organic insulating film 1002, anorganic insulating film 1005 disposed on the wire 1003 and the lowerelectrode 1004, a light-emitting stack 1006 disposed on the lowerelectrode 1004 and the organic insulating film 1005, an upper electrode1007 disposed on the light-emitting stack 1006, an opposing substrate1009, a sealant 1008, and a desiccant 1017. Thus, even if the wire 1003is a multilayer wire including, for example, Ti—Al—Ti layers, the spacesunder the overhangs of the uppermost layer are expected to be filledwith the organic insulating film 1005. However, as illustrated in FIGS.43(a) and 43(b), the organic insulating film 1005 extends from under thesealant 1008 to a portion located further inward of the sealant 1008.Thus, as illustrated in FIG. 44(b), if the organic insulating film 1005fails to completely block the intrusion paths extending along the sideportions of the wire 1003 due to a cause such as an adhesion of aparticle to the wire 1003 during the manufacturing process, moisture andoxygen would intrude into the sealed region through the clearancebetween the sealant 1008 and the organic insulating film 1005, asillustrated in FIG. 44(a).

In the organic EL element described in PTL 2, on the other hand, a gateline or a pixel electrode and the source lead electrode are made of thesame film. The source lead electrode is electrically connected to asource line having an overhanging shape in the sealed space and is drawnto the outside of the sealed space so as to cross the sealant. Thisconfiguration thus prevents moisture and oxygen from intruding into theinside of the element along the side portions of the source leadelectrode. The organic EL element described in PTL 2, however, has thefollowing problems. Firstly, the side portions of the source leadelectrode need to have a fine shape, for example, a forward taperedshape. Thus, the material of the source lead electrode and themultilayer structure of the source lead electrode have to be selectedfrom limited options. Furthermore, the source lead electrode needs to beconnected to the source line through a contact hole. This requirementmay bring about contact failure at the connection portion and reductionof yields. Moreover, reduction of the contact resistance at the contactportion usually requires surface treatment such as dry etching orchemical cleaning. Further, a region for forming a contact hole has tobe allocated, thereby increasing a frame region.

The embodiment of the invention is made in view of the above-describedsituation and aims to provide an organic EL display device that enablessize reduction of a frame and that has high reliability and highproductivity.

Solution to Problem

An aspect of the embodiment may be an organic electroluminescent displaydevice including a display region configured to display pixels; a frameregion configured to surround the display region; a substrate; anorganic electroluminescent element disposed on the substrate; a sealingmember configured to cover the organic electroluminescent element; alead wire disposed on the substrate and extending from a region coveredwith the sealing member to an outer side of the sealing member; and oneor more organic insulators disposed within the frame region instead ofwithin the display region. The lead wire may include two opposite sideportions. The one or more organic insulators may each cover part of atleast one of the two side portions. The sealing member may cover the oneor more organic insulators. Hereinbelow, this organic electroluminescentdisplay device is also referred to as a display device according to theembodiment.

Preferable embodiments of the display device according to the inventionare described below. The preferable embodiments described below may beappropriately combined together. An embodiment formed by combining twoor more of the preferable embodiments described below is also regardedas one preferable embodiment.

The one organic insulator or each organic insulator may be linearlydisposed so as to cross the lead wire and may cover part of each of thetwo side portions.

The one or more organic insulators may be provided in a plurality. Theplurality of organic insulators may each be disposed in an island form.At least one of the plurality of organic insulators may be disposed oneach of the two side portions. The plurality of organic insulators maybe arranged in a staggered manner.

The organic electroluminescent display device according to theembodiment may further include an edge cover. The organicelectroluminescent element may include a first electrode, anelectroluminescence layer stacked on the first electrode, and a secondelectrode stacked on the electroluminescence layer. The edge cover mayoverlap an edge portion of the first electrode. The one or more organicinsulators may be made of the same material as the edge cover.

The organic electroluminescent display device according to theembodiment may further include an inter-layer insulating film. Theorganic electroluminescent element may include a first electrode, anelectroluminescence layer stacked on the first electrode, and a secondelectrode stacked on the electroluminescence layer. The inter-layerinsulating film may be disposed between the first electrode and thesubstrate. The one or more organic insulators may be made of the samematerial as the inter-layer insulating film.

The substrate is a first substrate. The sealing member may include asecond substrate opposing the first substrate and a sealant that bondsthe first substrate and the second substrate together. The one or moreorganic insulators may be covered with the sealant.

The sealing member may include a barrier film formed by stacking aplurality of insulator films one on top of another. The plurality ofinsulator films may include an inorganic insulating film. The one ormore organic insulators may be covered with the barrier film.

The lead wire may include a first layer and a second layer stacked onthe first layer. The second layer may include an overhanging portionsticking out to a side of the first layer.

Advantageous Effects of Invention

The embodiment of the invention can provide an organic EL display devicethat enables size reduction of a frame and that has high reliability andhigh productivity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view of an organic EL display deviceaccording to the first embodiment.

FIG. 2 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 1.

FIG. 3 is a schematic plan view of the organic EL display deviceaccording to the first embodiment.

FIG. 4 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 3.

FIG. 5 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 3.

FIG. 6 is a schematic plan view of an organic EL display deviceaccording to a first comparative example.

FIG. 7 is a schematic cross-sectional view of the organic EL displaydevice according to the first comparative example and illustrates across-sectional structure taken along the line A-B in FIG. 6.

FIG. 8 is a schematic plan view of an organic EL display deviceaccording to a second comparative example.

FIG. 9 is a schematic cross-sectional view of an organic EL displaydevice according to the second comparative example and illustrates across-sectional structure taken along the line A-B in FIG. 8.

FIG. 10 is a schematic plan view of the organic EL display deviceaccording to the first embodiment.

FIG. 11 is a schematic plan view of the organic EL display deviceaccording to the first embodiment.

FIG. 12 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 10.

FIG. 13 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 10.

FIG. 14 is a schematic plan view of an organic insulator and a sealantof the organic EL display device according to the first embodiment.

FIG. 15 is a schematic plan view of the organic insulator and thesealant of the organic EL display device according to the firstembodiment.

FIG. 16 is a schematic plan view of the organic EL display deviceaccording to the first embodiment.

FIG. 17 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 16.

FIG. 18 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates the case wherea particle adheres to a lead wire.

FIG. 19 is a schematic cross-sectional view of the organic EL displaydevice according to the first embodiment and illustrates the case wherea particle adheres to a lead wire.

FIG. 20 is a schematic plan view of a first modified example of theorganic EL display device according to the first embodiment.

FIG. 21 is a schematic plan view of a first modified example of theorganic EL display device according to the first embodiment.

FIG. 22 is a schematic plan view of the organic EL display deviceaccording to a second embodiment.

FIG. 23 is a schematic cross-sectional view of the organic EL displaydevice according to the second embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 22.

FIG. 24 is a schematic cross-sectional view of the organic EL displaydevice according to the second embodiment and illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 22.

FIG. 25 is a schematic plan view of the organic EL display deviceaccording to the second embodiment.

FIG. 26 is a schematic plan view of a first modified example of theorganic EL display device according to the second embodiment.

FIG. 27 is a schematic plan view of a second modified example of theorganic EL display device according to the second embodiment.

FIG. 28 is a schematic plan view of the second modified example of theorganic EL display device according to the second embodiment.

FIG. 29 is a schematic plan view of an organic EL display deviceaccording to a third embodiment.

FIG. 30 is a schematic cross-sectional view of the organic EL displaydevice according to the third embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 29.

FIG. 31 is a schematic plan view of the organic EL display deviceaccording to the third embodiment.

FIG. 32 is a schematic cross-sectional view of the organic EL displaydevice according to the third embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 31.

FIG. 33 is a schematic cross-sectional view of the organic EL displaydevice according to the third embodiment and illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 31.

FIG. 34 is a schematic plan view of an organic EL display deviceaccording to a third comparative example.

FIG. 35 is a schematic cross-sectional view of the organic EL displaydevice according to the third comparative example and illustrates across-sectional structure taken along the line A-B in FIG. 34.

FIG. 36 is a schematic plan view of an organic EL display deviceaccording to a fourth comparative example.

FIG. 37 is a schematic cross-sectional view of the organic EL displaydevice according to the fourth comparative example and illustrates across-sectional structure taken along the line A-B in FIG. 36.

FIG. 38 is a schematic plan view of the organic EL display deviceaccording to the third embodiment.

FIG. 39 is a schematic plan view of the organic EL display deviceaccording to the third embodiment.

FIG. 40 is a schematic cross-sectional view of the organic EL displaydevice according to the third embodiment and illustrates across-sectional structure taken along the line A-B in FIG. 38.

FIG. 41 is a schematic cross-sectional view of the organic EL displaydevice according to the third embodiment and illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 38.

FIG. 42 is a schematic cross-sectional view of an organic EL displaydevice according to a fourth embodiment.

FIGS. 43(a) to 43(c) are schematic diagrams of the light emitting devicedescribed in PTL 1, where FIG. 43(a) is a cross-sectional view of thelight emitting device taken along the line A-B in FIG. 43(b), FIG. 43(b)is a plan view of the light emitting device, and FIG. 43(c) is across-sectional view of the light emitting device taken along the lineC-D in FIG. 43(b).

FIGS. 44(a) and 44(b) are schematic cross-sectional views of the lightemitting device described in PTL 1 and illustrates the case where aparticle adheres to a wire.

FIG. 45 is a schematic cross-sectional view of a second modified exampleof the organic EL display device according to the first embodiment.

FIG. 46 is a schematic plan view of a third modified example of theorganic EL display device according to the second embodiment.

FIG. 47 is a schematic cross-sectional view of a modified example of theorganic EL display device according to the third embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinbelow, the invention is described in further detail referring tothe drawings using embodiments. The invention, however, is not limitedto these embodiments.

First Embodiment

FIGS. 1 and 3 are schematic plan views of an organic EL display deviceaccording to the first embodiment. FIGS. 2, 4, and 5 are schematiccross-sectional views of the organic EL display device according to thefirst embodiment. FIG. 2 illustrates a cross-sectional structure takenalong the line A-B in FIG. 1. FIG. 4 illustrates a cross-sectionalstructure taken along the line A-B in FIG. 3. FIG. 5 illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 3.

An organic EL display device 101 according to the first embodiment is anactive-matrix-driven organic EL display device. As illustrated in FIG.2, the organic EL display device 101 includes a first substrate 1, asecond substrate 2 opposing the first substrate 1, and a sealant 3interposed between the substrates 1 and 2. The first substrate 1corresponds to a substrate of a display device according to theinvention. The second substrate 2 and the sealant 3 function as asealing member 4. The sealant 3 is disposed along the edge portion ofthe second substrate 2 so as to be in a frame form. The organic ELdisplay device 101 according to the first embodiment may be apassive-matrix-driven organic EL display device.

In this description, the edge portion means a portion located far fromthe center of the object and close to the outside.

As illustrated in FIG. 1, a display region 6 that displays an image isformed in a region surrounded by the sealant 3. Multiple pixels, notillustrated, arranged in a matrix are disposed in the display region 6.Each pixel may include subpixels of multiple colors (for example, threecolors of red, green, and blue). The organic EL display device 101according to the first embodiment may be a full-color display device ora monochrome display device. A frame-shaped frame region 5 is disposedaround the display region 6. The frame region 5 does not display animage. The sealant 3 is disposed in the frame region 5.

As illustrated in FIG. 2, thin film transistors (TFT) 7, signal lines 8,lead wires 9, an inter-layer insulating film 10, first electrodes 11,and an edge cover 12 are disposed on the first substrate 1. An organicinsulator 14 is disposed immediately above a portion of the lead wire 9.An electroluminescence layer (EL layer) 15 and a second electrode 16 aredisposed in this order on the first electrodes 11. The first electrodes11, the EL layer 15, and the second electrode 16 function as an organicEL element 17. Although not illustrated, a base coat layer, asemiconductor layer, a gate insulator film, an inter-inorganic-layerinsulating film, and a terminal connected to a mount component are alsodisposed on the first substrate 1. The signal lines 8 include wires suchas a gate wire and a source wire. Examples of a mount component includea driver or a driving circuit, such as a gate driver and a sourcedriver, and flexible printed substrates or flexible printed circuits.The driver may be monolithically formed on the first substrate 1.Hereinbelow, the first substrate 1 and components disposed on the firstsubstrate 1 are also collectively referred to as a TFT substrate.

The edge cover 12 has openings 13 (portions through which the firstelectrodes 11 are exposed) in correspondence with the pixels or thesubpixels. A light-emitting region is disposed in each opening 13. Thelight-emitting region forms each pixel or each subpixel. The edge cover12 is disposed on the inter-layer insulating film 10 and partiallyoverlaps the edge portions of the first electrodes 11. The inter-layerinsulating film 10 is interposed between the first electrodes 11 and thefirst substrate 1. More specifically, the inter-layer insulating film 10is disposed between the first electrodes 11 and electrically conductivemembers (such as the TFTs 7 or the signal lines 8) underlying the firstelectrodes 11. Each first electrode 11 is electrically connected withthe corresponding TFT 7 through a contact hole formed in the inter-layerinsulating film 10.

Either the first electrodes 11 or the second electrode 16function/functions as an anode and the other function/functions as acathode. In the case where the first electrodes 11 function as an anode,layers such as a hole injection layer, a hole transport layer, alight-emitting layer, an electron transport layer, and an electroninjection layer are sequentially stacked one on top of another on thefirst electrodes 11 to form the EL layer 15 and the second electrode 16is formed on the EL layer 15 to function as a cathode. A single one ofthese layers may have two or more functions. For example, instead ofseparately forming a hole injection layer and a hole transport layer, alayer concurrently functioning as a hole injection layer and a holetransport layer may be formed. In addition, a layer such as a carrierblocking layer may be appropriately inserted. In the case where thesecond electrode functions as an anode, these layers may be stacked oneon top of another in the opposite order.

In this description, the layers interposed between the first electrodeand the second electrode are collectively referred to as an EL layer.

The organic EL display device 101 according to the embodiment may beeither a bottom emission device that emits light from the TFT substrateside or a top emission device that emits light from the sealing member 4side. In the former case, transparent or semitransparent electrodes areused as the first electrodes 11 and a reflecting electrode is used asthe second electrode 16. In the latter case, the combination ofelectrodes opposite to those of the former is used. The opticalproperties of the first electrodes 11 and the second electrode 16, suchas a transmittance and a reflectance, are not limited to particular onesand may be appropriately determined.

A sealed region 18 enclosed by the first substrate 1 and the sealingmember 4 are sealed by the first substrate 1 and the sealing member 4.The organic EL element 17 disposed in the sealed region 18 is alsosealed by the first substrate 1 and the sealing member 4. Thisconfiguration prevents moisture and oxygen from intruding into thesealed region 18 from the outside and inhibits degradation of theorganic EL element 17. The space between the TFT substrate and thesecond substrate 2 may be filled with a resin material containing adesiccant and/or oxygen absorbent. A desiccant may be attached to thesurface of the second substrate 2 located closer to the TFT substrate.

As illustrated in FIG. 3, each lead wire 9 extends from the regioncovered with the sealing member 4, such as the display region 6, to aportion outside the sealing member 4 so as to cross the sealant 3. Thepurposes of the lead wires 9, that is, components to which the leadwires 9 are connected are not limited to particular ones and may beappropriately determined independent of one another. Examples ofcomponents to which the lead wires 9 are connected include the secondelectrode 16, the signal lines 8, a monolithic driving circuit, andterminals (not illustrated).

As illustrated in FIGS. 4 and 5, each lead wire 9 is a wire (multilayerwire) formed by stacking two or more layers one on top of another andpreferably has a configuration in which a lower layer 19, a middle layer20, and an upper layer 21 are stacked one on top of another in thisorder. More specifically, each lead wire 9 may have a Ti—Al—Timultilayer structure. The middle layer 20 and the upper layer 21respectively correspond to the first layer and the second layer of thedisplay device according to the invention.

As described below, the lead wires 9 are formed through aphotolithography process including wet etching or dry etching. Since theetching rate varies between two or more layers included in themultilayer wire, the amount by which the layers are side-etched duringwet etching or dry etching varies. Thus, both side portions 22 a and 22b of each lead wire 9, that is, two opposite side portions 22 a and 22 bare more likely to have an overhanging shape, that is, a shape in whichthe uppermost layer sticks out sideways. In this case, the upper layer21 includes overhanging portions 23 that stick out to the side of themiddle layer 20 from above the middle layer 20. As illustrated in FIG.3, the overhanging portions 23 are formed so as to extend along theoutline of the lead wire 9. The width of the middle layer 20 is smallerthan the width of the upper layer 21 and the width of the lower layer19. The etching rate of the middle layer 20 is higher than the etchingrates of the upper layer 21 and the lower layer 19. Thus, the middlelayer 20 is etched faster than the upper layer 21 and the lower layer19.

As illustrated in FIG. 3, the organic insulator 14 is formed in apattern of a single line (strip) extending so as to cross the multiplelead wires 9. As illustrated in FIGS. 3 and 4, the patterned organicinsulator 14 covers portions of the side portion 22 a and the sideportion 22 b of each lead wire 9.

A sealant region is disposed around the display region 6. In the sealantregion, a material of the sealant 3 (also referred to as a sealingmaterial, below) is applied to the first substrate 1 and the secondsubstrate 2 is bonded to the first substrate 1. The organic insulator 14is disposed in the frame region 5, specifically, in the sealant regionand not disposed in the display region 6. As described above, theorganic insulator 14 is a component separate from the inter-layerinsulating film 10 and the edge cover 12. The organic insulator 14 isneither connected with the inter-layer insulating film 10 and the edgecover 12 nor overlaps the edge portions of the first electrodes 11. Theentirety of the organic insulator 14 is covered with the sealant 3. Theentire periphery of the organic insulator 14 is closely attached to thesealant 3. Components such as the lead wires 9, the first substrate 1, asemiconductor layer, a gate insulator film, and an inter-inorganic-layerinsulating film, which may be disposed around the organic insulator 14,are all made of inorganic materials. The sealant 3 is closely attachedto these components made of inorganic materials around the organicinsulator 14.

Examples of the sealing material include ultraviolet cure and/orthermoset epoxy resins. The viscosity of these materials is normally ashigh as several hundred pascal-seconds. Thus, as illustrated in FIG. 5,the spaces under the overhanging portions 23 of each lead wire 9 cannotusually be filled with a sealing material. Examples of the method forforming the sealant 3 include application methods such as dispensing andscreen printing. The sealant 3 may have an oxygen-getter function.

Before describing the operation and effects of the embodiment, first andsecond comparative examples that the inventors have examined aredescribed below.

FIG. 6 is a schematic plan view of an organic EL display deviceaccording to the first comparative example. FIG. 7 is a schematiccross-sectional view of the organic EL display device according to thefirst comparative example and illustrates a cross-sectional structuretaken along the line A-B in FIG. 6.

In this comparative example, the organic insulator 14 is not disposed onthe lead wire 9, as illustrated in FIG. 6, and only the sealant 3 isdisposed on the lead wire 9. Thus, as illustrated in FIG. 7, the spacesunder the overhanging portions 23 of the upper layer 21 of the lead wire9 are not filled with the sealant 3 and gaps 25 occur between thesealant 3 and the side portions 22 a and 22 b of the lead wire 9. Thegaps 25 occur specifically between the middle layer 20 and the sealant3. Thus, paths for moisture and oxygen to intrude into the sealed region18 are formed along the side portions 22 a and 22 b.

FIG. 8 is a schematic plan view of an organic EL display deviceaccording to the second comparative example. FIG. 9 is a schematiccross-sectional view of the organic EL display device according to thesecond comparative example and illustrates a cross-sectional structuretaken along the line A-B in FIG. 8.

In this comparative example, as illustrated in FIG. 8, an organicinsulating film 26 that is not subjected to patterning is formed underthe sealant 3. The adhesion of the sealant to an organic insulator istypically poor. Thus, as illustrated in FIG. 9, the sealant 3 and theorganic insulating film 26 are more likely to be separated at theinterface therebetween and a clearance 27 occurs therebetween. Thus, apath for moisture and oxygen to intrude into the sealed region 18 isformed between the sealant 3 and the organic insulating film 26.

FIGS. 10 and 11 are schematic plan views of the organic EL displaydevice according to the first embodiment. In FIG. 11, the arrowsindicate intrusion paths for moisture and oxygen and the cross marksindicate block points on the intrusion paths.

In this embodiment, as illustrated in FIG. 10, each lead wire 9 has aportion covered with the organic insulator 14 and portions left withoutbeing covered with the organic insulator 14. As illustrated in FIG. 11,the intrusion path extending along the side portion 22 a or 22 b of thelead wire 9 is thus blocked at the portion covered with the organicinsulator 14 (see solid arrows and cross marks). At the portions leftwithout being covered with the organic insulator 14, the intrusion pathbetween the sealant 3 and the organic insulator 14 is blocked (seesolid-white arrows and cross marks). In this manner, the likelihood ofmoisture and oxygen intruding into the sealed region 18 can be reduced,whereby degradation of the organic EL element can be inhibited.

The operation and effects are described further in detail with referenceto FIGS. 12 and 13.

FIGS. 12 and 13 are schematic cross-sectional views of the organic ELdisplay device according to the first embodiment. FIG. 12 illustrates across-sectional structure taken along the line A-B in FIG. 10 and FIG.13 illustrates a cross-sectional structure taken along the line C-D andthe line E-F in FIG. 10.

As illustrated in FIG. 12, the side portions 22 a and 22 b of each leadwire 9 are partially covered with the organic insulator 14, not with thesealant 3 generally having poor covering properties. Thus, the organicinsulator 14 is also situated under the overhanging portions 23, so thatgaps that can occur under the overhanging portions 23 can be reduced insize. This configuration can thus effectively prevent moisture andoxygen from intruding into the sealed region 18 along the side portion22 a or 22 b.

Here, most or the entirety of the spaces under the overhanging portions23 is preferably filled with the organic insulator 14. Specifically,almost no or no clearances are preferably left between the organicinsulator 14 and the side portions 22 a and 22 b of each lead wire 9.This configuration can effectively block each intrusion path formoisture and oxygen along the side portion 22 a or 22 b, and morereliably prevent intrusion of moisture and oxygen.

As described above, the adhesion of the sealant to the organicinsulating film is generally poor and the sealant 3 and the organicinsulator 14 are more likely to be separated at the interfacetherebetween also in this embodiment. Thus, as illustrated in FIG. 12,it is concerned that moisture and oxygen may intrude into the sealedregion 18 through a clearance 28 that occurs between the sealant 3 andthe organic insulator 14. In this embodiment, however, instead of anorganic insulating film that has not been patterned, the patternedorganic insulator 14 is disposed. Moreover, the organic insulator 14 iscovered with the sealant 3, as illustrated in FIGS. 10 and 13. Thus, theintrusion path between the sealant 3 and the organic insulator 14 can beeffectively blocked by the sealant 3. This configuration can thuseffectively prevent moisture and oxygen from intruding into the sealedregion 18 through the space between the sealant 3 and the organicinsulator 14.

Now, the adhesion of the sealant 3 to the organic insulator 14 isfurther described.

FIGS. 14 and 15 are schematic plan views of the organic insulator andthe sealant of the organic EL display device according to the firstembodiment. FIG. 16 is a schematic plan view of the organic EL displaydevice according to the first embodiment. FIG. 17 is a schematiccross-sectional view of the organic EL display device according to thefirst embodiment and illustrates a cross-sectional structure taken alongthe line A-B in FIG. 16.

The adhesion of the sealant 3 to the organic insulator 14 is assumed tochange depending on the pattern of the organic insulator 14. Asillustrated in FIG. 15, the adhesion of the organic insulator 14 to thesealant 3 at the middle portion of the organic insulator 14 is assumedto decrease with increasing area of the organic insulator 14, morespecifically, increasing lengthwise and widthwise dimensions. Thisphenomenon possibly relates to the membrane stress. Thus, the separationat the interface between the sealant 3 and the organic insulator 14 isassumed to be less likely to occur with decreasing lengthwise andwidthwise dimensions of the organic insulator 14, as illustrated in FIG.14, and more likely to occur with increasing lengthwise and widthwisedimensions of the organic insulator 14, as illustrated in FIG. 15. Inaddition, it is assumed that the adhesion of the organic insulator 14 tothe sealant 3 improves further toward the edge portion of the organicinsulator 14. Thus, in this embodiment, as illustrated in FIGS. 16 and17, it is assumed that the adhesion between the sealant 3 and theorganic insulator 14 is particularly poor at the middle portion (portionsurrounded by a broken line) of the organic insulator 14 and thus anintrusion path for moisture and oxygen is likely to be formed at theportion. However, the sealant 3 and the organic insulator 14 are capableof being closely attached to each other at the edge portion of theorganic insulator 14, so that it can be expected that the intrusion pathfor moisture and oxygen can be blocked at the edge portion.

FIGS. 18 and 19 are schematic cross-sectional views of the organic ELdisplay device according to the first embodiment and illustrate the casewhere a particle adheres to a lead wire.

Also in this embodiment, as in the case of PTL 1, the intrusion pathextending along the side portion 22 a or 22 b of the lead wire 9 mayhave a portion having insufficient blockage, as illustrated in FIG. 18,due to a cause such as adhesion of a particle 29 to the lead wire 9during a manufacturing process and the intrusion path may be furtherconnected to an intrusion path between the sealant 3 and the organicinsulator 14, as illustrated in FIG. 19. Even in this case, however, theintrusion path can be blocked at the edge portion of the organicinsulator 14 since the organic insulator 14 is formed only within thesealant region and covered with the sealant 3. Thus, this embodimentattains a more reliable device than a device formed by the technologydescribed in PTL 1.

Unlike the technology described in PTL 2, this embodiment does notrequire fine shaping of the side portions 22 a and 22 b of the lead wire9. Thus, the selection of the materials and the multilayer structures ofthe lead wire 9 is widened. Unlike the technology described in PTL 2,this embodiment does not require connection of the lead wire 9 to a wireon the upper layer or the lower layer at or near the sealant 3. Thus,the points at which the lead wire 9 is connected to other wires can bereduced, whereby contact failures can be reduced and the yields canconsequently be improved. In addition, the surface treatment forreducing the contact resistance at the contact points can be omitted,whereby the manufacturing processes can be reduced. Furthermore, contactholes used for the lead wire 9 to be connected to other wires can bereduced, whereby the area of the frame region 5 can be reduced.

As described above, this embodiment can attain an organic EL displaydevice that enables size reduction of a frame and that has highreliability and high productivity.

The following describes a method for manufacturing an organic EL displaydevice 101 according to this embodiment. The following mainly describesthe case where a top-gate process is adopted as a manufacturing processof the TFT 7, but a bottom-gate process may be adopted, instead. In thatcase, the processing following the formation of the inter-layerinsulating film 10 flows similarly.

Firstly, the first substrate 1 is prepared. The first substrate 1 is aninsulating substrate. In the case of a bottom emission device, the firstsubstrate 1 is transparent, whereas in the case of a top emissiondevice, the first substrate 1 may be either transparent orsemitransparent. Specific examples include a glass substrate and aplastic substrate.

Subsequently, a base coat layer and a semiconductor layer are formed onthe first substrate 1 in this order by a general method.

Then, a gate insulator film is formed by a general method.

Then, a gate wire is formed by a general method.

In the case where the bottom-gate process is adopted, the gate wire maybe a wire formed by stacking two or more layers (multilayer wire).Examples of the specific multilayer structure include a Ti—Al—Tistructure, a Mo—Al—Mo structure, a Ti—Cu—Ti structure, and a Mo—Cu—Mostructure. These materials are described in the order of the upperlayer, the middle layer, and the lower layer.

In either the top-gate process or the bottom-gate process, one or moreelectrically conductive films are formed by a method such as sputteringand then photolithography process including wet etching or dry etchingis performed so that the one or more electrically conductive films arepatterned. Thus, a gate wire is formed.

Subsequently, an inter-inorganic-layer insulating film is formed by ageneral method. Examples of the material of the inter-inorganic-layerinsulating film include silicon oxide, silicon nitride, and siliconoxynitride. The inter-inorganic-layer insulating film may be formed bystacking two or more films one on top of the other. Examples of themethod for forming the inter-inorganic-layer insulating film includeplasma CVD.

Subsequently, contact holes that pass through the gate insulator filmand the inter-inorganic-layer insulating film are formed by a generalmethod such as photolithography.

Thereafter, a source wire and the lead wires 9 are formed. Since thesource wire is formed by the same process as the lead wire 9, the sourcewire has the same multilayer structure. Each layer of the source wireand the lead wires 9 is usually made of an inorganic electricallyconductive film. Examples of the material of each layer include metalmaterials such as aluminum (Al), copper (Cu), silver (Ag), tungsten (W),molybdenum (Mo), titanium (Ti), and tantalum (Ta), compounds of thesemetal materials (for example, oxides and nitrides), and electricallyconductive transparent materials such as indium tin oxide (ITO) andindium zinc oxide (IZO). Examples of a method for depositing eachinorganic electrically conductive film include sputtering. After two ormore inorganic electrically conductive films are deposited, thephotolithography process including wet etching or dry etching isperformed so that the two or more inorganic electrically conductivefilms are patterned. Thus, the source wire and the lead wires 9 areformed. Since the etching rate varies between the two or more inorganicelectrically conductive films, the amount by which those films areside-etched during wet etching or dry etching varies. Thus, the sideportions 22 a and 22 b of each lead wire 9 may have an overhangingshape. Specific examples of the multilayer structure of the lead wire 9include a Ti—Al—Ti structure, a Ti—Cu—Ti structure, a Mo—Al—Mostructure, an ITO—Ag (or Ag alloy)-ITO structure, an IZO—Ag (or Agalloy)-ITO structure, and an IZO—Al (or Al alloy)-IZO structure. Thesematerials are described in the order of the upper layer, the middlelayer, and the lower layer.

Also in the case where the bottom-gate process is adopted, the sourcewire and the lead wires 9 may have the same structure and material andmay be formed by the same method as those in the case where the top-gateprocess is adopted. Thus, the side portions 22 a and 22 b of each leadwire 9 may have an overhanging shape also in this case.

The following mainly provides a description assuming the case where eachlead wire 9 has a Ti—Al—Ti multilayer structure.

The lead wires 9 may be formed in the process in which the gate wire isformed, not in the process in which the source wire is formed. In thecase where a multilayer wire is adopted as a gate wire and the leadwires 9 are formed in the process in which the gate wire is formed, theamount by which the two or more electrically conductive films areside-etched during wet etching or dry etching varies because the etchingrate in the photolithography process varies between these films. Thus,particularly in the case where the bottom-gate process is adopted, theside portions 22 a and 22 b of the lead wires 9 may have an overhangingshape. This case is described in a second modified example.

Subsequently, the inter-layer insulating film 10 is formed. Examples ofthe method for forming the inter-layer insulating film 10 include amethod including exposure to light and development after applying aphotosensitive resin film onto the first substrate 1 by spin coating orslit coating and a method including direct drawing using an inkjetdevice. Examples of the material of the inter-layer insulating film 10include acrylic resin, polyimide, phenol resin, and siloxane resin.During development of the inter-layer insulating film 10, the Al layerof each lead wire 9 may be recessed by being damaged by a developingsolution and the side portions 22 a and 22 b may have an apparentoverhanging shape.

After the lead wires 9 are formed and before the inter-layer insulatingfilm 10 is formed, an inter-inorganic-layer insulating film (notillustrated and also referred to as a second inter-inorganic-layerinsulating film, below) different from the above-describedinter-inorganic-layer insulating film (also referred to as a firstinter-inorganic-layer insulating film, below) may additionally beformed. Examples of the second inter-inorganic-layer insulating filminclude silicon oxide, silicon nitride, and silicon oxynitride. Thesecond inter-inorganic-layer insulating film may be formed by stackingtwo or more films. Examples of the method for forming the secondinter-inorganic-layer insulating film include plasma CVD. Openings areformed in the second inter-inorganic-layer insulating film by a generalmethod such as photolithography. Contact holes that pass through thesecond inter-inorganic-layer insulating film and the inter-layerinsulating film 10 are then formed. The first electrodes 11 areelectrically connected with the TFTs 7 through the contact holes. Thestructure formed in this case is described below as a second modifiedexample.

Subsequently, the first electrodes 11 are formed. In the case of the topemission device, the first electrodes 11 are formed of a reflectivefilm. Examples of the material of the reflective film include metalmaterials such as Ag and Al and alloys of these metal materials. In thecase of the top emission device, the first electrodes 11 may be formedof a multilayer film including a reflective film and a film made of anelectrically conductive transparent material such as ITO or IZO(electrically conductive transparent film). Specific examples of themultilayer structure include an IZO—Al—IZO structure, an ITO—Ag-ITOstructure, and an IZO—Ag—IZO structure. These materials are described inthe order of the upper layer, the middle layer, and the lower layer.Examples of the method for forming the reflective film and theelectrically conductive transparent film include sputtering. After oneor more such electrically conductive films are formed, photolithographyprocess including wet etching is performed so that the one or moreelectrically conductive films are patterned. Thus, the first electrode11 is formed. Patterning of a reflective film made of a Ag-based orAl-based material in the photolithography process involves the use of anetchant such as mixed acid containing phosphoric acid, acetic acid, andnitric acid and an aqueous or solvent removal solution. Thus, the Allayer of each lead wire 9 may be recessed by being damaged by theetchant and the removal solution during etching and resist removal,whereby the side portions 22 a and 22 b may have an apparent overhangingshape.

In the case of the top emission device, the lead wires 9 may be formedin the process in which the first electrodes 11 is formed, not in theprocess in which the source wire is formed. In the case where the firstelectrodes 11 and the lead wires 9 are concurrently formed from the samemultilayer film, the amount by which the two or more electricallyconductive films are side-etched during wet etching varies because theetching rate in the photolithography process varies between these films.Thus, in the case of the top emission device and when the lead wires 9and the first electrodes 11 are concurrently formed from the samemultilayer film, the side portions 22 a and 22 b of each lead wire 9 mayhave an overhanging shape.

In the case of the bottom emission device, the first electrodes 11 areformed of an electrically conductive transparent or semitransparentfilm. Examples of the material of the electrically conductive filminclude electrically conductive transparent materials such as ITO andIZO. Examples of depositing the electrically conductive film includesputtering. After the electrically conductive film is deposited, thephotolithography process including wet etching is performed so that theelectrically conductive film is patterned. Thus, the first electrodes 11are formed. When the electrically conductive film formed of ITO or IZOis patterned in the photolithography process, an etchant such as oxalicacid and an aqueous or solvent removal solution are used. Thus, the Allayer of each lead wire 9 may be recessed by being damaged by theremoval solution during resist removal and the side portions 22 a and 22b may have an apparent overhanging shape.

Subsequently, the edge cover 12 is formed. Examples of the method forforming the edge cover 12 include a method including exposure to lightand development after applying a photosensitive resin film onto thefirst substrate 1 by spin coating or slit coating and a method includingdirect drawing using an inkjet device. Examples of the material of theedge cover 12 include acrylic resin, polyimide, phenol resin, andsiloxane resin. During development of the edge cover 12, an Al layer ofeach lead wire 9 may be recessed by being damaged by a developingsolution and the side portions 22 a and 22 b may have an apparentoverhanging shape.

Subsequently, the organic insulator 14 is formed. The organic insulator14 is made of an organic insulating material. Examples of the method forforming the organic insulator 14 include a method including exposure tolight and development after applying a photosensitive resin film ontothe first substrate 1 by spin coating or slit coating and a methodincluding direct drawing using an inkjet device. Examples of thematerial of the organic insulator 14 include acrylic resin, polyimide,phenol resin, and siloxane resin.

The film thickness of the organic insulator 14 is preferably greaterthan or equal to the film thickness of the lead wires 9. Thisconfiguration allows the side portions 22 a and 22 b of the lead wires 9to be sufficiently covered. Specifically, the film thickness of theorganic insulator 14 preferably falls within the range of approximatelyfrom 1 μm to 5 μm.

Since there is a need to prevent the intrusion of moisture and oxygeninto the sealant 3, the width of the organic insulator 14 (dimension inwhich the lead wire 9 extends) is set smaller than the width of thesealant. Specifically, the width of the organic insulator 14 preferablyfalls within the range of approximately from 2 μm to 500 μm. The widthof the organic insulator 14 may be or may not be uniform. In otherwords, the width of the organic insulator 14 may change in thelongitudinal direction of the organic insulator 14.

In this embodiment, the accuracy required for patterning the organicinsulator 14 is lower and introduction of an inkjet device forpatterning the organic insulator 14 is easier than in the case where apattern is formed within the display region 6. Thus, a material having alow moisture permeability and that is different from the material ofother insulating layers can be used as the material of the organicinsulator 14. In this embodiment, the element deterioration can be moreeffectively inhibited than in the case of the fourth embodiment,described below.

Subsequently, layers forming the EL layer 15 are sequentially formed.Each layer of the EL layer 15 is usually formed so as to cover thedisplay region 6 by a method such as mask vapor deposition and thusetching is not required here. The material of each layer of the EL layer15 is not limited to a particular one and can be appropriately selectedfrom general materials.

Subsequently, the second electrode 16 is formed. This formation of thesecond electrode 16 completes the organic EL element 17. The secondelectrode 16 is usually formed so as to cover the display region 6 by amethod such as mask vapor deposition and thus etching is not requiredhere.

In the case of a top emission device, the second electrode 16 is formedof a transparent or semitransparent electrically conductive film.Examples of the material of this electrically conductive film includeelectrically conductive transparent materials such as ITO and IZO.

In the case of a bottom emission device, the second electrode 16 isformed of a reflective film. Examples of the material of the reflectivefilm include metal materials such as Ag and Al and alloys of these metalmaterials. In the case of the bottom emission device, the secondelectrode 16 may be formed of a multilayer film including a reflectivefilm and a film made of an electrically conductive transparent materialsuch as ITO or IZO (electrically conductive transparent film).

Subsequently, the first substrate 1 on which the organic EL element 17is disposed and the second substrate 2 are bonded together using asealant, so that the organic EL element 17 is sealed.

Finally, a process for mounting a mount component is performed, so thatthe organic EL display device 101 according to this embodiment isfinished.

FIGS. 20 and 21 are schematic plan views of a first modified example ofthe organic EL display device according to the first embodiment. In FIG.21, the arrows indicate intrusion paths of moisture and oxygen and thecross marks indicate the block points on the intrusion paths.

In this modified example, as illustrated in FIG. 20, multiple organicinsulators 14 are formed into a pattern of multiple lines (strips). Eachorganic insulator 14 crosses the multiple lead wires 9. As illustratedin FIG. 21, each of the intrusion paths (see solid arrows and crossmarks) extending along the side portion 22 a or 22 b of the lead wire 9and each of the intrusion paths (see solid-white arrows and cross marks)between the sealant 3 and the organic insulating film 26 become morelikely to be blocked with increasing number of organic insulators 14,whereby the element deterioration can be more effectively inhibited.Specifically, this modified example can attain a more reliable organicEL display device compared to the case where only one organic insulator14 is provided.

FIG. 45 is a schematic cross-sectional view of a second modified exampleof the organic EL display device according to the first embodiment.

In this modified example, (1) the lead wires 9 are formed in the processin which the gate wire is formed, not in the process in which the sourcewire is formed, or (2) the lead wires 9 are formed in the process inwhich the source wire is formed. Then, a second inorganic insulatingfilm is formed over the lead wires 9. Thus, as illustrated in FIG. 45, afirst or second inter-inorganic-layer insulating film 24 is formed overthe lead wires 9. The inter-inorganic-layer insulating film 24 hasalmost no effect of flattening the steps in the pattern underlying theinter-layer insulating film 24. Thus, if the film thickness of theinter-inorganic-layer insulating film 24 is insufficient, the coverageof the inter-inorganic-layer insulating film 24 may be insufficient ator near the side portions 22 a and 22 b. However, a gap that can occurat or near the insufficient coverage portion of theinter-inorganic-layer insulating film 24 can be filled with the organicinsulator 14 on the inter-inorganic-layer insulating film 24. Thus, theintrusion path extending along the side portion 22 a or 22 b of the leadwire 9 can be blocked also in this modified example.

In the above-described case (1), the inter-inorganic-layer insulatingfilm 24 may be removed in the sealant region at the time of formingcontact holes passing through the gate insulator film and theinter-inorganic-layer insulating film 24. In the above-described case(2), the inter-inorganic-layer insulating film 24 may be removed in thesealant region at the time of forming openings. Thus, the organicinsulator 14 may be located immediately above the lead wires 9 as in theabove-described case.

Second Embodiment

Except for the organic insulator having a different pattern, thisembodiment is substantially the same as the first embodiment. Thus, thecharacteristics unique to this embodiment are mainly described in thisembodiment and portions that are the same as those in the firstembodiment are not described. Throughout this embodiment and the firstembodiment, components having the same or similar functions are denotedby the same symbols and are not described in this embodiment.

FIG. 22 is a schematic plan view of an organic EL display deviceaccording to the second embodiment. FIGS. 23 and 24 are schematiccross-sectional views of the organic EL display device according to thesecond embodiment. FIG. 23 illustrates a cross-sectional structure takenalong the line A-B in FIG. 22. FIG. 24 illustrates a cross-sectionalstructure taken along the line C-D and the line E-F in FIG. 22.

As illustrated in FIGS. 22 to 24, an organic EL display device 102according to the embodiment includes multiple organic insulators 14.Each organic insulator 14 is formed in an island form (dot-like form).The patterned organic insulators 14 are individually disposed on theside portions 22 a and 22 b of each lead wire 9. The multiple organicinsulators 14 are located in a scattered manner and each organicinsulator 14 covers part of the side portion 22 a or 22 b underlying theorganic insulator 14. Each organic insulator 14 is covered with thesealant 3.

The film thickness of the organic insulator 14 is preferably greaterthan or equal to the film thickness of the lead wire 9. Thisconfiguration allows the side portions 22 a and 22 b of the lead wire 9to be sufficiently covered. Specifically, the film thickness of theorganic insulator 14 preferably falls within the range of approximatelyfrom 1 μm to 5 μm.

Since there is a need to prevent the intrusion of moisture and oxygeninto the sealant 3, the width of the organic insulator 14 (dimension inwhich the lead wire 9 extends) is set smaller than the width of thesealant. Specifically, the width of the organic insulator 14 preferablyfalls within the range of approximately from 2 μm to 500 μm. The size ofthe multiple organic insulators 14 may be the same or different.

FIG. 25 is a schematic plan view of the organic EL display deviceaccording to the second embodiment. In FIG. 25, the arrows indicate theintrusion paths for moisture and oxygen and the cross marks indicate theblock points on the intrusion paths.

In this embodiment, each organic insulator 14 is disposed in an islandform (dot-like form). Each organic insulator 14 covers part of one ofthe two opposite side portions 22 a and 22 b of the corresponding leadwire 9 and does not cover the other side portion. Thus, as illustratedin FIG. 25, the configuration according to this embodiment can have morepoints at which and a larger area over which the intrusion path formoisture and oxygen between the sealant 3 and the organic insulator 14can be blocked than in the case of the first embodiment (see solid-whitearrows and cross marks). The configuration according to this embodimentthus more reliably blocks this intrusion path than in the case of thefirst embodiment. Each intrusion path extending along the side portion22 a or 22 b of the lead wire 9 is blocked as in the case of the firstembodiment (see solid arrows and cross marks). In this manner, theelement deterioration can be more effectively inhibited in thisembodiment than in the case of the first embodiment.

FIG. 26 is a schematic plan view of a first modified example of theorganic EL display device according to the second embodiment.

In this modified example, part of each lead wire 9 does not cross thesealant 3 and is formed, for example, so as extend along the sealant 3,as illustrated in FIG. 26. Even in such a case, forming multiple organicinsulators 14 in an island form can achieve the same effects as in thecase illustrated in FIG. 22 without producing a complex layout design.

FIGS. 27 and 28 are schematic plan views of a second modified example ofthe organic EL display device according to the second embodiment. InFIG. 28, the arrows indicate the intrusion paths for moisture and oxygenand the cross marks indicate the block points on the intrusion paths.

In this modified example, as illustrated in FIG. 27, multipleisland-like (dot-like) organic insulators 14 are formed on each of theside portions 22 a and 22 b of the lead wire 9. Each organic insulator14 covers part of the side portion 22 a or 22 b underlying the organicinsulator 14.

As illustrated in FIG. 28, each of the intrusion paths (see solid arrowsand cross marks) extending along the side portion 22 a or 22 b of thelead wire 9 and each of the intrusion paths (see solid-white arrows andcross marks) between the sealant 3 and the organic insulating film 26become more likely to be blocked with increasing number of organicinsulators 14, whereby the element deterioration can be more effectivelyinhibited.

FIG. 46 is a schematic plan view of a third modified example of theorganic EL display device according to the second embodiment.

In this modified example, the multiple organic insulators 14 are formedin a staggered manner and alternately arranged as illustrated in FIG.46. This configuration allows the distance between adjacent organicinsulators 14 to be increased compared to the cases illustrated in FIGS.22 and 27, whereby connection between adjacent organic insulators 14,that is, occurrence of patterning failures of the organic insulators 14can be prevented. This configuration can thus more reliably bring aboutan effect of the second embodiment with which the element deteriorationis effectively inhibited.

Third Embodiment

Except for the sealing member having a different structure, thisembodiment is substantially the same as the first embodiment. Thus, thecharacteristics unique to this embodiment are mainly described in thisembodiment and portions that are the same as those in the firstembodiment are not described. Throughout this embodiment and the firstembodiment, components having the same or similar functions are denotedby the same symbols and are not described in this embodiment.

FIGS. 29 and 31 are schematic plan views of the organic EL displaydevice according to the third embodiment. FIGS. 30, 32, and 33 areschematic cross-sectional views of the organic EL display deviceaccording to the third embodiment. FIG. 30 illustrates a cross-sectionalstructure taken along the line A-B in FIG. 29. FIG. 32 illustrates across-sectional structure taken along the line A-B in FIG. 31. FIG. 33illustrates a cross-sectional structure taken along the line C-D and theline E-F in FIG. 31.

As illustrated in FIGS. 29 to 33, an organic EL display device 103according to the third embodiment includes a barrier film 30 serving asthe sealing member 4 instead of the second substrate 2 and the sealant3.

The sealed region surrounded with the first substrate 1 and the barrierfilm 30 is sealed with the first substrate 1 and the barrier film 30.The organic EL element 17 disposed in the sealed region is also sealedwith the first substrate 1 and the barrier film 30. This configurationprevents moisture and oxygen from intruding into the sealed region fromthe outside and inhibits deterioration of the organic EL element 17.

The barrier film 30 is formed over the first substrate 1 except for amount region over which terminals are disposed and a mount component ismounted (terminal region). The barrier film 30 completely covers thedisplay region 6 and a large part of the first substrate 1. In addition,the barrier film 30 covers the entirety of the organic insulator 14formed on the lead wires 9.

The barrier film 30 has a multi-layer structure in which two or moreinsulator films are stacked. For example, the barrier film 30 includes alower layer film 31 and an upper layer film 32 stacked on the lowerlayer film 31, as illustrated in FIG. 30. The lower layer film 31, whichis a lowermost layer of the barrier film 30, is formed of an inorganicinsulating film. Examples of the specific multilayer structure of thebarrier film 30 include an inorganic insulating film-organic insulatingfilm-inorganic insulating film structure (three-layer structure) and aninorganic insulating film-organic insulating film-inorganic insulatingfilm-organic insulating film-inorganic insulating film structure(five-layer structure).

Examples of the material of the barrier film 30, that is, each insulatorfilm include an inorganic insulating material and an organic insulatingmaterial. Examples of the inorganic insulating material include siliconoxide, silicon nitride, silicon oxynitride, and aluminium oxide.Examples of the organic insulating material include acrylic resin andpolyimide. Examples of the method for depositing the inorganicinsulating film include plasma CVD and sputtering. The inorganicinsulating film deposited by such methods has almost no effect offlattening the steps of the pattern underlying the inorganic insulatingfilm. Thus, as illustrated in FIG. 33, if the film thickness of thelower layer film 31 is insufficient and the shape of the side portions22 a and 22 b of the lead wire 9 is distorted, the coverage of the lowerlayer film 31 of the barrier film 30 may be insufficient at or near theside portions 22 a and 22 b. However, the insufficient coverage portioncan be covered with the second layer or subsequent film, for example,the upper layer film 32. Thus, the barrier film 30 as a whole canfunction as the sealing member 4 without any problem. Examples of themethod for depositing an organic insulating film include an applicationmethod including spin coating or slit coating.

Hereinbelow, before describing the operation and the effects accordingto the embodiment, third and fourth comparative examples that theinventors have examined are described.

FIG. 34 is a schematic plan view of the organic EL display deviceaccording to the third comparative example. FIG. 35 is a schematiccross-sectional view of the organic EL display device according to thethird comparative example and illustrates a cross-sectional structuretaken along the line A-B in FIG. 34.

In this comparative example, as illustrated in FIG. 34, only a barrierfilm 30 is disposed on the lead wire 9 without the organic insulator 14being disposed on the lead wire 9. Thus, as illustrated in FIG. 35, thelower layer film 31 of the barrier film 30 fails to cover the sideportions 22 a and 22 b distorted into an overhanging shape and the lowerlayer film 31 is not filled into the spaces under the overhangingportions 23 of the upper layer 21 of the lead wire 9. Consequently, gaps25 occur between the barrier film 30 and the side portions 22 a and 22 bof the lead wire 9. The gaps 25 particularly occur between the middlelayer 20 of the lead wire 9 and the barrier film 30. Thus, paths formoisture and oxygen to intrude into the sealed region are formed alongthe side portions 22 a and 22 b.

FIG. 36 is a schematic plan view of an organic EL display deviceaccording to the fourth comparative example. FIG. 37 is a schematiccross-sectional view of an organic EL display device according to thefourth comparative example and illustrates a cross-sectional structuretaken along the line A-B in FIG. 36.

In this comparative example, as illustrated in FIG. 36, an organicinsulating film 26 that has not been subjected to patterning is formedunder the edge portion of the barrier film 30. Generally, the adhesionof the inorganic insulating film included in the barrier film to theorganic insulator is poor and thus the lower layer film 31 of thebarrier film 30 and the organic insulating film 26 are likely to beseparated at the interface between the lower layer film 31 and theorganic insulating film 26 and a clearance 34 occurs between the lowerlayer film 31 and the organic insulating film 26. Thus, a path formoisture and oxygen to intrude into the sealed region is formed betweenthe barrier film 30 and the organic insulating film 26.

FIGS. 38 and 39 are schematic plan views of the organic EL displaydevice according to the third embodiment. In FIG. 39, the arrowsindicate the intrusion paths for moisture and oxygen and the cross marksindicate the block points on the intrusion paths. FIGS. 40 and 41 areschematic cross-sectional views of the organic EL display deviceaccording to the third embodiment. FIG. 40 illustrates a cross-sectionalstructure taken along the line A-B in FIG. 38 and FIG. 41 illustrates across-sectional structure taken along the line C-D and the line E-F inFIG. 38.

In this embodiment, as illustrated in FIG. 38, the lead wire 9 has aportion covered with the organic insulator 14 and portions left withoutbeing covered with the organic insulator 14. Thus, as illustrated inFIGS. 39 and 40, each of the intrusion paths extending along the sideportion 22 a or 22 b of the lead wire 9 is blocked at the portioncovered with the organic insulator 14 (see solid arrows and crossmarks). At the portions left without being covered with the organicinsulator 14, the intrusion paths between the sealant 3 and the organicinsulator 14 are blocked (see solid-white arrows and cross marks), asillustrated in FIGS. 39 and 41. In this manner, the likelihood ofmoisture and oxygen intruding into the sealed region can be reduced,whereby degradation of the organic EL element can be inhibited.

As illustrated in FIG. 41, insufficient coverage portions 33 of thelower layer film 31 are formed on the outer side of the organicinsulator 14 and between the organic insulator 14 and the display region6 (on the inner side of the organic insulator 14) and can form intrusionpaths for moisture and oxygen. However, the organic insulator 14 iscapable of blocking the intrusion of moisture and oxygen in the manneras described above, even when moisture and oxygen intrude along theinsufficient coverage portion 33 on the outer side. Moreover, since theinsufficient coverage portion 33 on the inner side is covered with theupper layer film 32, the intrusion of moisture and oxygen from above thebarrier film 30 can also be prevented. Thus, these insufficient coverageportions 33 do not particularly cause any problem.

As in the case of the first embodiment, this embodiment can attain anorganic EL display device that enables size reduction of a frame andthat has high reliability and high productivity.

In the case where the barrier film 30 includes an organic insulatingfilm, the organic insulating film is formed over the entire area of thefirst substrate 1 except for the mount region and thus unable tosubstitute for the organic insulator 14.

FIG. 47 is a schematic cross-sectional view of a modified example of theorganic EL display device according to the third embodiment.

In this modified example, as illustrated in FIG. 47, the lower layerfilm 31 of the barrier film 30 has a large film thickness. Thus, thelower layer film 31 causes no coverage failure at or near the sideportions 22 a and 22 b. In this case, however, gaps 25 occur between thelower layer film 31 and the side portions 22 a and 22 b of the lead wire9. Thus, the above-described organic insulator (not illustrated in FIG.47) is disposed in order to block the intrusion path extending along theside portion 22 a or 22 b of the lead wire 9. Thus, the likelihood ofmoisture and oxygen intruding into the sealed region can be reduced,whereby degradation of the organic EL element can be inhibited.

In this modified example, with the presence of the lower layer film 31,the organic insulating film fails to fill into the gaps 25 even bystacking the organic insulating film on the lower layer film 31. Thus,also in this modified example, the organic insulating film of thebarrier film 30 is unable to substitute for the organic insulator 14.

Fourth Embodiment

Except for the organic insulator having a different material and formedby a different production flow, this embodiment is substantially thesame as the first embodiment. Thus, the characteristics unique to thisembodiment are mainly described in this embodiment and portions that arethe same as those in the first embodiment are not described. Throughoutthis embodiment and the first embodiment, components having the same orsimilar functions are denoted by the same symbols and are not describedin this embodiment.

FIG. 42 is a schematic cross-sectional view of an organic EL displaydevice according to the fourth embodiment.

As illustrated in FIG. 42, in an organic EL display device 104 accordingto the fourth embodiment, thin film transistors (TFTs) 7, signal lines8, a lead wire 9, an inter-layer insulating film 10, first electrodes11, and an edge cover 12 are disposed on the first substrate 1. Anorganic insulator 14 is also formed on part of the lead wire 9. Theorganic insulator 14 is made of the same material of the inter-layerinsulating film 10 or the edge cover 12 and formed so as to cover partof at least one side portion of the lead wire 9.

The patterns described in the first and second embodiments can beappropriately adopted as a pattern of the organic insulator 14. Thepattern of the organic insulator 14 may be a pattern of at least oneline (strip) disposed in a direction that crosses the lead wire 9 or maybe an island-like (dot-like) pattern in which at least one portion ofthe organic insulator 14 is disposed on each of the side portions 22 aand 22 b of the lead wire 9.

In the case where the organic insulator 14 is made of the same materialas the inter-layer insulating film 10, the pattern of the organicinsulator 14 is concurrently formed in the process of forming theinter-layer insulating film 10 described in the first embodiment. Inthis case, the process for forming the organic insulator 14 described inthe first embodiment is not required.

However, in the case where the lead wire 9 is formed together with thefirst electrodes 11 in the process for forming the first electrodes 11,the organic insulator 14 is not allowed to be formed in the process forforming the inter-layer insulating film 10 since the organic insulator14 needs to be formed after the process for forming the first electrodes11.

In the case where the organic insulator 14 is formed using the samematerial as the edge cover 12, the pattern of the organic insulator 14is concurrently formed in the process for forming the edge cover 12described in the first embodiment. In this case, the process for formingthe organic insulator 14 described in the first embodiment is notrequired.

As in the case of the first embodiment, this embodiment can attain anorganic EL display device that enables size reduction of a frame andthat has high reliability and high productivity.

In addition, this embodiment enables reduction of the production processsince the pattern of the organic insulator 14 on the lead wire 9 and theinter-layer insulating film 10 or the edge cover 12 in the displayregion can be concurrently formed from the same material. In otherwords, this embodiment attains an organic EL display device that hashigher productivity than that of the organic EL display device accordingto the first embodiment.

In the first to fourth embodiments, the case where the lead wireincludes overhanging portions has been described. However, the structureand the shape of the lead wire are not limited to particular ones. Thestructure of the lead wire may be, for example, a single layerstructure. The shape of the lead wire may be a forward tapered shape ora reverse tapered shape. Nevertheless, in the case where the lead wireincludes overhanging portions, deterioration of the organic EL elementis likely to proceed particularly in this structure and thusdeterioration of an organic EL element can be particularly effectivelyinhibited in this case.

The above-described embodiments may be appropriately combined within thescope not departing from the gist of the invention. The modifiedexamples of each embodiment may be combined with other embodiments. Forexample, the patterns of the organic insulators described in the firstand second embodiments may be combined. Alternatively, for example, abarrier film may be formed and the sealant and the second substrate mayalso be used for sealing.

REFERENCE SIGNS LIST

-   -   1 first substrate    -   2 second substrate    -   3 sealant    -   4 sealing member    -   5 frame region    -   6 display region    -   7 thin film transistor (TFT)    -   8 signal line    -   9 lead wire    -   10 inter-layer insulating film    -   11 first electrode    -   12 edge cover    -   13 opening    -   14 organic insulator    -   15 EL layer    -   16 second electrode    -   17 organic EL element    -   18 sealed region    -   19 lower layer    -   20 middle layer    -   21 upper layer    -   22 a, 22 b side portion    -   23 overhanging portion    -   24 first or second inter-inorganic-layer insulating film    -   25 gap    -   26 organic insulating film    -   27, 28, 34 clearance    -   29 particle    -   30 barrier film    -   31 lower layer film    -   32 upper layer film    -   33 insufficient coverage portion    -   101, 102, 103, 104 organic EL display device

1. An organic electroluminescent display device, comprising: a displayregion that displays pixels; a frame region that surrounds the displayregion; a substrate; an organic electroluminescent element disposed onthe substrate; a sealing member that covers the organicelectroluminescent element; a lead wire disposed on the substrate andextending from a region covered with the sealing member to an outer sideof the sealing member; and a organic insulator disposed within the frameregion instead of within the display region, wherein the lead wireincludes two side portions of a first layer and a second layer stackedon the first layer, the second layer includes an overhanging portionsticking out to a side of the first layer, and the organic insulatorcovers the two side portions and fills under the overhanging portion. 2.The organic electroluminescent display device according to claim 1,wherein the sealing member covers the organic insulator and a portion ofthe second layer of the lead wire.
 3. The organic electroluminescentdisplay device according to claim 2, wherein the sealing member has aspace under the overhanging portion disposed in the portion of thesecond layer of the lead wire.
 4. The organic electroluminescent displaydevice according to claim 1, wherein the substrate consists of foursides in a periphery, and wherein the lead wire is disposed on one sideand is not disposed on other three sides.
 5. The organicelectroluminescent display device according to claim 1, wherein the leadwire is connected to a monolithic driving circuit.
 6. The organicelectroluminescent display device according to claim 1, furthercomprising a source wire, the source wire having a same multilayerstructure as the lead wire.
 7. The organic electroluminescent displaydevice according to claim 1, the lead wire further comprising a thirdlayer, the first layer being stacked on the third layer, wherein thethird layer includes an another overhanging portion sticking out to aside of the first layer.
 8. The organic electroluminescent displaydevice according to claim 7, wherein the organic insulator fills betweenthe overhanging portion and the another overhanging portion.
 9. Theorganic electroluminescent display device according to claim 7, whereina width of the another overhanging portion is larger a width of theoverhanging portion.
 10. The organic electroluminescent display deviceaccording to claim 7, wherein the second layer and the third layer arecomposed of a same metal material.
 11. The organic electroluminescentdisplay device according to claim 7, wherein the first layer is composedof aluminum, wherein the second layer is composed of titanium, andwherein the third layer is composed of titanium.